On September 26, just before the season was to begin, young Atlanta Thrashers star Dany Heatley crashed his Ferrari in suburban Atlanta. The passenger, Thrashers workhorse Dan Snyder, was killed. Heatley himself was badly injured and eventually charged with vehicular homicide. The entire NHL thus began the season in mourning.

The most surprising teams were the Tampa Bay Lightning in the Eastern Conference and San Jose Sharks in the Western Conference. The Lightning, who had a remarkable season with only 20 man-games lost to injury, finished atop the Eastern Conference. The Sharks, who were firmly in rebuilding mode after a disastrous 28-37-9-8 campaign the last season, came second in the Western Conference and won the Pacific Division.

Goaltending was also the story of the Presidents' Trophy-winning Detroit Red Wings as the return from retirement of legend Dominik Hasek bumped Curtis Joseph to the minor leagues. At the same time long time back up Manny Legace put up better numbers than both veterans and won the starting job in the playoffs.

Of note is the fact that the Nashville Predators made the playoffs for the first time in franchise history. They put up a valiant effort but were unable to overcome the Hockey Hall of Fame-bound roster of the Red Wings in the first round.

Red-shaded team won the Presidents' Trophy and home-ice advantage throughout the playoffs.

Orange-shaded team clinched the other conference.

Yellow-shaded teams clinched the other four divisions.

Green-shaded teams clinched the remaining ten playoff berths.

Numbers in parentheses indicate ranking in conference. Division leaders are automatically ranked 1-3. These three, plus the next five teams in the conference standings, earn playoff berths at the end of the season.

The 2004 playoffs were considered to be wide open with no clear favourite. All of the top teams had weaknesses. Tampa Bay and Boston were both young teams with no history of recent postseason success. Detroit, Ottawa, Colorado, and Philadelphia all had major questions in goal. New Jersey was marred by injuries to Scott Stevens and Brian Rafalski, while Vancouver was missing the suspended Todd Bertuzzi.

The first-round Eastern Conference matchups were notable for the number of heated rivalries. The Ottawa Senators met the Toronto Maple Leafs for the fourth time in five years in the always passion-filled Battle of Ontario. The Boston Bruins and Montreal Canadiens met in a resumption of the most common of all NHL playoff series, and one which the Canadiens have thoroughly dominated, including an upset win two years prior. The Philadelphia Flyers also played a hated division rival in the New Jersey Devils. The only non-rivalry was the Tampa Bay-New York Islanders series.

The West saw the resumption of the Vancouver-Calgary rivalry, which had been somewhat dormant as the Flames had missed the playoffs for seven years in a row. In a less passionate but still interesting matchup, Detroit played division rival Nashville, whom they had struggled against during the regular season in Nashville's first ever franchise visit to the playoffs. San Jose met the St. Louis Blues, while the always difficult four-five matchup saw Colorado and Dallas meet.

The Flames and the Lightning battled hard in the Stanley Cup Finals, eventually pushing the series to seven games. By game 5, the Flames took the 3-2 series lead back to Calgary, and in game six, a puck appeared to have gone into the net, which would have made the game 3-2, but the goal light did not go on, the referee did not signal that a goal had been scored, and play went on, no goal counted. Extensive replays showed the play was inconclusive. The Lightning would win the game in over time, and go on to win the Stanley Cup with a 2-1 win in game seven, with two goals from Ruslan Fedotenko. Brad Richards, with a team-high 25 points in the playoffs, was awarded the Conn Smythe Trophy.